Broiler chickens and turkeys represent a large part of the protein eaten in countries around the world. Accordingly, poultry growing is a very large industry. The economics of this commodity are such that very small increases in efficiency and pricing have a significant effect on the profitability of the individual farmer. For example, the weight-to-feed conversion is a key measure of how much food it takes to make a pound of saleable meat. A typical number is 1.65 lb feed to make 1 pound of chicken meat. An increase of 1 point (0.01) represents savings of several million dollars per year.
The USDA grades meat into categories. Grade A is the best grade. Chicken meat that is Grade A is worth $0.05-0.10/lb more than Grade B. Birds with disease are downgraded. For example, turkeys with cellitus cannot be Grade A. Chicken “paws” are a delicacy for some consumers. A Grade A paw can be worth $0.50 more than a sub-grade paw. Paws with lesions, for example, from standing on high pH litter are not Grade A. If a higher percent of a flock is Grade A, the farmer's profitability is increased.
Poultry (chickens, turkeys, ducks, geese and the like) are grown commercially in large barns. Feed is automatically delivered to feeders strategically placed in the barn. Variable height watering stations are also placed throughout the barn. The poultry stand on litter, typically composed of pine bark, but also of any suitable substrate such as disclosed by Keithly et al [U.S. Pat. Nos. 6,708,647, 6,860,233 and 6,523,496], including dried citrus peels, saw dust, pine wood shavings and mixtures thereof.
Growing birds excrete body fluids onto the surface of the litter bed, gradually building up a manure cake. The uric acid in the excrement (up to 50%) breaks down into ammonia and other compounds. The ammonia raises the pH of the bed, causing sores on the feet and breasts of the birds. Insects, such as darkling beetles, live in the manure-coated litter. These beetles bite the birds, opening up vectors for infection and disease.
The ammonia release stresses the birds, can blind young birds, and stunt, the growth of all birds. The U.S. Occupational Safety & Health Administration (OSHA) defines the 8 hour permissible exposure limit (PEL) for ammonia as 50 ppm. Additionally, the birds have a characteristic odor which limits where poultry barns can be sited.
Rehberger, U.S. Pat. No. 5,945,333, discloses the use of bacillus and other specific bacterial types to treat litter beds to reduce ammonia by disrupting the gram negative bacteria which inherently convert uric acid to ammonia. The '333 patent also discloses the addition of acid-generating bacteria to neutralize the produced ammonia and reduce the pH below 7. At a pH<7, ammonia remains soluble in water and is not volatile.
Penaud, U.S. Pat. No. 6,025,187, discloses the mixture of bacillus and lactobacillus bacteria on poultry waste to create complex proteins from the various nitrogen nutrients.
A second, commercially important, poultry litter treatment (PLT) involves adding low molecular weight acid (e.g. sodium bisulfate) to the litter bed to inhibit the conversion of uric acid to ammonia and to prevent the volatilization of the produced ammonia. These chemical treatments work until the chemical is consumed, usually about half way through the grow-out. PLT is a neutral, dry granule as applied, but with the addition of poultry-produced water, the pH falls to 4.
After each flock, the farmer typically rakes off the manure cake and turns or fluffs the litter. The useful life of the litter bed can be extended by these strategies, but eventually the litter has to be removed. Disposal of spent litter is increasingly difficult. In Delaware, for example, spent litter must be land filled.
Humic acid is a naturally-occurring very complex array of carboxylic acid groups in a buffering inorganic matrix. Nature designs humic acid as a transport molecule for moving cations and the like into plant roots.
In an article by Senn & Kingman, “A review of Humus and Humic Acids”, 1973, Research Series 145, SC Agricultural Experiment Station, Clemson, S.C., the authors write: “Chemically, humus consists of certain constituents of the original plant material resistant to further decomposition; of substances undergoing decomposition; of complexes resulting from decomposition, either by processes of hydrolysis or by oxidation and reduction; and of various compounds synthesized by microorganisms.”
Natural humic acid is inherently insoluble and comes from a wide variety of sources. In fact the actual chemistry is so complex that the complete structure is unknown and currently unknowable. The attributes of humic acid from different sources are different. Those skilled in the art describe different humic acid by the source. For example, some of the most useful humic acids come from brown coal, particularly Leonardite. Other humic acids come from Histosol, a peat derivative from the top meter of a peat bog.
Phillips, U.S. Pat. No. 6,656,723, describes an odor controlling and organic waste degrading composition from a chemically reactive lignin complex comprising a Histosol-derived compound with a structural group devoid of carboxylic acid groups and a microorganism capable of providing hydrolytic enzymes.
A humic acid from Leonardite is treated with caustic and oxygen to fragment the native humic acid, create carboxylic acid functional groups and render the fragments water soluble @pH 9-10.
Native humic acid, from every source, is inherently alive with bacteria. It is well known that bacteria live through four stages: Lag phase, where growth is about to begin; Log growth where bacteria count increases exponentially; Stationary growth where as many bacteria die as reproduce; and Endogenous or log death where bacteria consume each other when food stuff is scarce. In indigenous populations, the bacterial population is in all 4 stages simultaneously. The native population stays in balance and changes in response to the nutrient availability, water level, temperature, oxygen and the like.
Non indigenous bacteria can be added which upsets this balance as disclosed, for example, by Rehberger. Added bacteria are typically preserved with a chemical preservative, low pH, refrigerated temperature, low water activity and the like during distribution. Preservatives typically preserve bacteria in all 4 stages of life. Thus once unpreserved, the natural balance is preserved.
A system that kept bacteria in lag growth until unpreserved would have special advantage because the once-unpreserved bacteria would substantially all be in exponential growth.
A particularly useful composition would be lag growth-preserved heterotrophic bacteria with water soluble humic acid from brown coal.
Soluble humic acid fragments have peculiar attributes. The exposed carboxylic acid groups adsorb on the surface of the bacteria. The unattached carboxylic acid groups protect the bacteria by capturing multivalent cations, such as heavy metals. Some of the fragments are absorbed by the bacteria, stimulating growth.